In E-UTRAN (Evolved Universal Terrestrial Radio Access Network), discussions have recently taken place concerning device-to-device communication (to be referred to as D2D communication hereinafter) that is a technique of allowing a plurality of terminal devices (User Equipment: to be referred to as UE hereinafter) to do direct communication without an intervention of a base station device.
D2D communication is executed using, for example, some of radio resources used in uplink of cellular communication such as LTE. The distance between terminal devices to which the D2D communication can be applied is said to be several hundred m. In 3GPP (3rd Generation Partnership Project) Release 12, a method of causing a terminal device to detect a terminal located in the vicinity and a method of broadcasting data to unspecified terminal devices have been proposed (for example, see NPL 1 or 2).